Evening star. [volume] (Washington, D.C.) 1854-1972, 1887-07-30

A BRILLIANT SKY GLOW.
The Causes OF Wednesday Nights Dis
play Discussed by Prof. Hazen.
THE VOLCANO Dust THEORY AND REASONS WHICH
TEND TO UPSET IT-THE NOTION OF THE CURRENTS
OF THE UPPER ARA NOVEL GERMAN THEORY
SOMETHING ABOUT THE CLOUDS AND THEIR MOVE
NENTS.
There was very brilliant sky glow on Wednes-
DAY night which attracted the interests OF scien-
lists and was admired and wondered at by many
people. For many minutes there was gorgeous
display OF rosy light extending entirely across the
heavens and around the entire horizon. 1t was a
similar display to that which occurred In the fall
OF 1883 and at the time caused such a wide dis
cusslon among scientists and aroused an active
general interest," only It was much more brill ant
and beautiful on this occasion than then. Prof.
H. Allen Hazen, OF the Signal ONCE, who took OBJ
servations OF the phenomenon, says:
"The sky coloring was first noticed by me at
Pm on ,UH II as very
60 above the horizon-Just Including the planet
venus. Its maxinum Intensity was at 40, and
pearance was similar to that Of the beautiful sky
coloring OF S3 l carefully observed the glows at
that time. and find that the glow Of Wednesday
ton. This would seem to indicate that the for
mer appearances were due to an intensfcatiOn OF
M sne sunset phenomenon. as is held by Prof. Simon
THE VOLCANO DUST THEORY.
'1nthe English Journal, Nature, there appeared
on the 18th OF May, quite long discussion by
Hon. Ralph Abercromby, on the connection be-
tween Krakatoa dust and these sky cOlOr1ngs Mr..
AOercrOmby asserts that in Two voyages 'around
| the world" he observed the movements OF the
regions and found it very dinicuit indeed, except
at rare intervals, TO note any motion at all. Leay-
Ing out OF the account the difficulty one would
have In observing such motions while travelling or
s at sea q mean Will in motion) stu this
views in regard to upper-current movements
and snN,,ss vsiocties o are becoming very much
modned as observations increase. Instead or the
uniform directions and great continuous move
ments once regarded satisfactory, We now ind
movements Of high and low areas Of pressure as
are the surface winds. In the United States
{midtie latitudes, II a great and extensive high
area is over place or TO the eastward, the very
highest cirrus are either stationary or have
slow motion to the west. On Mt. Washington, n
H., $500 feet above sea Level, when high area is
over the station, or within 100 miles on either
side, the mean wind velocity is 2l miles
per hour, but when low area is near or over the
summit the mean velocity Is over 53 miles per
hour. This win help us In understanding the enor-
nous veocitieS OF cirrus (Over 100 miles per hour
noted few times by Nj. HldebrandSson In Up
saia. Sometimes, with low area near, the wind
reaches loo miles per hour On Mount Washington,
and once 1t reached 200 miles Upsala is GOO miles
farther north than Mount Washington, and as we
go north, up to certain latitude, the upper cur
rents increase In velocity. 1t Is very plain that
velocity much greater than 100 miles per hour
might occur in cirrus clouds In front or rear OF a
storm at Upsaia, but this is not the average
velocity, nor would it continue more than a few
hundred miles in any direction. Can anything
whatever be inferred from all this TO velOcLieS
or motions near The equator? think most en-
phaticaliy no. We are, however, by no means
ignorant OF
MOTIONS OF UPPER CLOUDS
In the equatorial regions. The following are the
facts first as to direction and second as to velocity:
observations OF upper clouds have been carefully
made In these portions OF the earth at various
points. The earliest and most satisfactory coiec-
lion Of these that have found is in CoIin's winds
OF the GLOBE In this work, with a few eXcep-
tions the directions from the east or from point
north OF east, at places north OF the equator. In
'MeteOrOlOgy OF India published by Blanford
find the average direction OF the wind in August
and september at high stations near the equator
as loiiows: Wellington, latitude 10 N, height
N. So W.. velocity 5 miles per hour; at Newera
kilya, latitude n, height about 6.l5O feet
records for Twelve years n. 90 W., velocity miles
per hour.
brier study Of the obs ,rvat1ons of upper clouds
as reported TO the United States from inter.
has shown nearly uniform direction (tron the
eaSD, though, at times there are most reina bic
exceptions, which hope 10 present more fuliy in
another place. A most important consideration Is
the height OF these clouds. believe no careful
measurement has ever been made, but from
various considerations would place The superior
limit at 1900 feet, though / think they rarely
reach TO- OUO.
FROM WEST TO EAST
AS to directions above this height Us ZOO feep
We must consider the motions OF volcanic ashes
that have been traced to their source, as well as
dust that has been carried thousands OF miles,
The evidence, up to August "a, 1889 is all
one way, and that is that the extreme upper cur
rent moves from west to east. believe that no
w nar rQf CT Dk~,.
can come TO any other conclusion.
When we come to study the velOcities of these
as Sw none az ALL and TINS
Is precisely what air. AbercrOmby observed. On
the mountain stations In India above noted the
mean velocity is 4.5 miles per hour at 900 feet
have no data for the maximum velocity, but very
much doubt II 1t ever reaches 80 miles per hour
and whatever IL is it certainly is not from the
east. In studying The motions OF the upper clouds
as reported to the international bulletin one i'm
mediateiy recognizes the extreme siowness Of
when clouds are abundant l find at Havana.
Cuba, latitude % degrees, out of 1O3 observations
OF high clouds Il were calm, and at Kingston,
Jamaica, latitude Is degrees out OF IlS records OF
cirrus 81 were calm.
NOVEL GERMAN THEORY
1t seems to me the evidence is overwhelming
that near the equator the surface trades have al
most constant and relatively great velocity from
an easterly point; that this velocity gradually
dimtnsheS we rise In the atmosphere till 1t be-
comes zero at 20 600 to $4,000 feet and after that
point IS reached the currents begin to have
tendency In the opposite direction. This evidence
was so convincing to Prot klessling, OF Germany
(who probably has paid more attention to this
subject than any one else), that he was forced to
abandon the view that upper currents had any
thing to do with the first distribution OF KrakatOa
ashes, and sought relief in the theory
that the ashes were carried above the
earth's attraction, and above the region OF
atmospheric friction so far, that they remained
suspended as cloud, while the earth rotated from
west to east underneath them. This is very in
gentous and, 1t must be confessed, would account
tiOns be made. hardly think, however that any
physics Of repute will agree with Prof KieSS-
ling. Whatever caused the glOws, am sure every
who viii look into the question in the light OF
our knowledge OF the upper currents will admit it
could not have been krakatOa ashes mechan1-
cally distributed. It seems to me the animated
discussion so far carried on can but add very
terialiy to the science OF meteOrOlOgy, though 1t
may seem that q final solution OF the question
may not be reached Till our appliances Tor and
methods OF observing natures laws and forces
have been extended far beyond their present
scope. Mr.. AbercrOmby has submitted that the
upper currents, over the West India Islands, are
from the west but he still thinks this Is not the
case over mid-Ocean. As the original glOws nearly
covered the whole earth, it will be seen that the
upper currents must be continuous from east to
west over the globe, and any departure from this
would be fatal to the original hypothesis"
Yellow Fever.
TWO INFECTED VESSELS IN QUARANTINE OFF PHILA-
DRLPA4A.